Air-brake



(Ne Model.)

A. P. MASSEY. AIR BRAKE.

No. 414.717'. Patented Nov. 12, 1889.

INVENTUR WITNESSES U ITED STATES PATENT OFFICE.

ALBERT P. MASSY, OF XVATERTOlN- N, NEXV YORK.

AlR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 414, 717, date&November 12, 1889.'

Application filed May 23, 1889. Serial Ne. 311,'789. (No model.)

To coll'whom it may conccrn:

Be it known that I, ALBERT P. MASSEY, a citizen of the United States,residing in the city of W'atertown, in the County of J eferson and Stateof New York, have invented certain new and useful In'provenents in Air-Brakes, of which the following, takenin connection with theaccornpanying drawing, is a specification.

My invention relates to an 'improvement in the means for actuatingcar-brakes, and

' is for the purposes of insuring a quick release and to prevent leakingon.

The drawing is a sectional View of the invention.

In the drawing, l is a train-pipo attached to the body ot' 'a car, as iscommon with brakes actuated by fiuid-pressure. l

2 is a branch pipe connecting the trainpipe with one end of cylinder 3.A reservoir el is connected with the opposite end of cylinder 3, and apiston 5, with one side exposecl to the pressure in the reservoir, is

fitted to the cylinder.

6 is a port leading from the cylinder 3 to the reservoir l. Acheck-valve 7 is located in port 6, which pernits air to pass only fromcylinder 3 to 1'eservoirl,'except as hereinatter described. 11 is aleakagegroove in said check-valve. A cap S gives access to valve 7. Thepiston-rod 9 may be connected with any of the systems ot' lcvers usedfor applying brakes.

10 is a gland for packing the piston-red. The piston is shown in the endof the cylinder, where it should be when brakes are off. The port 6 islocated near the end`ot the oylinder, so that no air can pass from thetrainpipe to the reservoir until the piston has reached nearly the endof its stroke.

The operation of the apparatus is* as follows: If the car were connectedwith the &Vestinghouse system of automatic, bra-hes, a certain pressurewould be maintained in train pipe l, which could be varied at will by asuitable valve and pump on the locomotive. As one end of cylinder 3is'in open communication through pipe 2 with pipe 1, the same pressurewould always obtain in cylinder 3 that was in train-pipo 1. lvith thepiston in the position shown air would pass through port 6 andcheck-valve 7 to reservoir 4 until the'pressure in the reservoir wasequal to that in the cylinder. The piston 5 would then have the samepressure on both sides, and

therefore be in equilihriu m. If, now, the' pressure should he reducedin the cylinder, the piston would no longer be in eqnilibrium, but wouldbe moved by the excess of pressure in the reservoir and produce atension on piston-rod 9 equal to the difference between the pressures inthe reservoir and the train-pipe fore any air could pass through theport 6 and reach the rcservoir 4:.

This iusures a quick release. It' *the train-pipo should be rupturedfron any cause, the pressure would be immediately reduced to zero incylinder 3, and the brakes consequently applied with full forceautomatically. When a car is cut off from a train, it the cocks in theends of the train-pipo are first closed, the pressure in the train-pipewould be maintained and the brakes would remain off; but if there was aslight leak the pressure in the cylinder would be gradually reduced anda gradnal strain be brought on the piston and brakelevers, or what iscalled leaking on would occur. To obviate this, the check-valve isfitted looselyor with a small groove cut in it, so that a slight leakagewould occur from the reservoir to the cylinder. p'ressurcwere reduced iery slowly in the trainpipe, the air in the reservoir would leak by thecheck-valve and equilibriuin be maintained on both sides of piston 5.YVhen the'brake is applied in actual service, the piston passes port (5before the slack of the brakes is taken up, and then the check-valve isopen on both Therefore, if the IOO sides to the reservoi'; hence thereservoirpressure against the piston cannot leak off and is maintainedindefinitely.

What I claim as new, and desh-e to protect .by Letters Patent, is-

' 'In a car-breke, a double-acting piston, a cylinder, a passage locatedin the wall of the cylinder near one end, so that the piston Will'passit in the early part of its stroke, and a IO check-valve containinga Ieakage-groove 10- cated in said passage, substantially as set forth.

In testinony Whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, on this 20th day I 5 of May, A.D. 1889. V

i ALBERT P. MASSEY.

'witnesses: u

HENRY W. BOYER, l/IICHAEL J. MORKIN,

